Correspondence (letter to the editor): Addenda Required

The radiation dose of an investigation using multidetector spiral computed tomography (MDCT) with contrast medium is 5–8 mS, which equates to a risk of radiation cancer of 1:10³–1:10⁴ (1). The article does not mention that when using MDCT, a pulmonary embolism is actually found in only 20–32% of patients in whom this is suspected.

80–92% of patients with acute pulmonary embolism have a deep vein thrombosis of the leg. If a deep vein thrombosis is confirmed and pulmonary embolism is clinically suspected at the same time, then the German guidelines regard this as confirmed pulmonary embolism. Complete venous compression ultrasonography (CCUS) can be used to reliably identify deep vein thromboses in the calf and thigh, and we conduct CCUS as our primary diagnostic evaluation in suspected pulmonary embolism after scoring and, if required, D-dimer testing (2).

Transesophageal echocardiography, as mentioned in the article, successfully confirms central pulmonary embolism in less than 10% of patients in whom this diagnosis is suspected. A new method—endobronchial ultrasonography (EBUS)—is available, which was developed primarily for staging the mediastinal lymph nodes in bronchus carcinoma. Since the pulmonary artery branch, the right and left pulmonary arteries, and the lobar pulmonary artery extend alongside the bronchi at a distance of 1–2 mm, it is possible to use this technique to confirm central pulmonary embolism—from the pulmonary valve to the lobar arteries— in more than 95% of patients (3). Only 15% of all symptomatic pulmonary embolisms are peripheral in isolation.

Endobronchial ultrasonography can be used in all patients with pulmonary embolism, whether high risk or low risk, and constitutes an alternative in renal failure, pregnancy, contrast medium allergy, hemodynamic instability in intensive care, and in patients refusing angio-CT because of the radiation exposure. The method is yet to be evaluated in multicenter studies.